A jet designed to fly at more than seven times the speed of sound has been tested in the Australian desert.

Researchers believe the scramjet could revolutionise long-haul air travel - cutting the trip from London to Sydney to just two hours - and substantially cut the cost of putting small payloads into space.

We've just got to analyse
the data now but it all seemed to basically work

Dr Allan PaullProject leader

The hypersonic engine was strapped on to a rocket and blasted more than 300 kilometres (190 miles) into the sky from a base at Woomera.

Scientists hope the engine will have worked under its own power on its descent to Earth - reaching a target speed of Mach 7.6 just before hitting the ground.

Scramjets have no moving parts and grab the oxygen they need to burn their fuel from the atmosphere.

Recovering wreckage

The first ever free flight of a scramjet was conducted by the US Defense Advanced Research Projects Agency (Darpa) 11 months ago. But its conceptual engine was fired from a gun in an enclosed facility on the ground.

The Queensland test would be the first successful flight in the open atmosphere.

The university has been working on scramjets for more than 15 years

This was the second time the University of Queensland team had attempted to fly the small HyShot engine. Its first test last year failed when the launch rocket malfunctioned.

The university scientists say their experiment on Tuesday went smoothly in perfect conditions, but stress it will be another few days before they will know for sure if everything worked properly.

What is left of the hypersonic engine crashed into the desert 400 km (250 miles) west of Woomera and will now be recovered.

The test took just eight minutes to complete, and data collected during this time are now being analysed.

"It was a world first in what it attempted to do and we certainly did what we attempted to do, but whether or not the results were as we hoped we don't know," project leader Dr Allan Paull said.

More efficient

The hope is that, during its fall back to Earth, the scramjet engine will have reached a top speed of 2.4 km/sec (8,600 km/h or 5,340 mph).

The technology was first proposed in the 1950s and 60s. Scramjets are much lighter than conventional engines that produce the same power.

Most of their propellant, in the form of oxygen, comes from the atmosphere. This is drawn into the engine, compressed and mixed explosively with a small amount of hydrogen.

However, this process only starts happening efficiently at Mach 5, which means conventional rocket technology is required to get the scramjets to their critical operating speed.

Whilst much of the attention surrounding scramjets has focussed on the shorter journey times they could bring to long-haul passenger air travel, the first applications are likely to be in the space delivery business - launching small payloads, such as communications satellites, into orbit.